Combining SOA and Cloud Computing
To my surprise, the combination of SOA (Service-oriented Architecture) and Cloud Computing (basically outsourcing the server management/using many virtual machines) was described as something new in IEEE Computer’s October issue (“Software Engineering Meets Services and Cloud Computing”, Stephen S . Yau and Ho G. An, pp. 47 – 53).
Besides the fact, that this is nothing new, but an ongoing trend that started a couple of years ago, there are three observations I’l like to share:
- The list of characteristics of a good service interface does not list API versioning, which is very important for mission critical applications that are mainly based on Web services. Otherwise these applications will break very often.
- Also, the API should be “stateless”, according to the authors. In reality, you want to use some sort of state for sessions (a shared token is common) and for transactions (to bundle a couple of API calls and only permanently store the data, when everything was successful).